title: Immunogenicity and safety of a measles-mumps-rubella-varicella vaccine following a 4-week or a 12-month interval between two doses.
abstract: BACKGROUND
  The MMRV combination vaccine, Priorix-Tetra™, is currently licensed in several European countries using a two-dose schedule in infants aged ≥9 months, with a preferred 6-week to 3-month interval between doses. This study was undertaken to generate safety and immunogenicity data for two doses of MMRV vaccine administered according to dose schedules using the shortest permitted interval of 4 weeks versus a longer interval of 12 months, which would allow flexible adaptation to local immunization calendars.
  
  
  METHODS
  Healthy children aged 11-13 months were randomized (1:1:1) to receive 2 doses of either: MMRV vaccine with a 4-week interval between doses (MMRV-4W group, N=188), MMRV vaccine with a 12-month interval between doses (MMRV-12M group, N=184), or MMR vaccine with a 4-week interval between doses (MMR group, N=187). Blood samples were taken prior to, and 4-6 weeks after each vaccination.
  
  
  RESULTS
  Post-Dose 2, both MMRV groups exhibited an adequate immunogenic response for all components; however the MMRV-12M group showed significantly greater geometric mean titers for mumps, rubella and varicella. Two varicella breakthrough cases occurred within the 12-month interval between doses in the MMRV-12M group. Local and general reactogenicity results were similar for all groups except for the MMRV-4W group, which had a greater incidence of fever during Days 0-14 post-Dose 1.
  
  
  CONCLUSIONS
  Two doses of MMRV vaccine administered in the second year of life elicited adequate immunogenicity and were well-tolerated whether administered with a dose interval of 4 weeks or 12 months.
authors.affiliation: Vaxinostics BV, University Vaccine Center Rotterdam Nijmegen, Rotterdam, The Netherlands. rumke@vaxinostics.com
authors.forename: H C
authors.initials: HC
authors.lastname: Rümke
authors.forename: H P
authors.initials: HP
authors.lastname: Loch
authors.forename: K
authors.initials: K
authors.lastname: Hoppenbrouwers
authors.forename: C
authors.initials: C
authors.lastname: Vandermeulen
authors.forename: A
authors.initials: A
authors.lastname: Malfroot
authors.forename: K
authors.initials: K
authors.lastname: Helm
authors.forename: M
authors.initials: M
authors.lastname: Douha
authors.forename: P
authors.initials: P
authors.lastname: Willems
mesh_terms: D000367:Age Factors; D019433:Chickenpox Vaccine / Q000008:administration & dosage / Q000009:adverse effects* / Q000276:immunology*; D005260:Female; D006801:Humans; D007114:Immunization / Q000379:methods*; D007115:Immunization Schedule; D007117:Immunization, Secondary / Q000379:methods*; D007223:Infant; D008297:Male; D022542:Measles-Mumps-Rubella Vaccine / Q000008:administration & dosage / Q000009:adverse effects* / Q000276:immunology*; D017778:Vaccines, Combined
chemical_list: D019433:Chickenpox Vaccine; D022542:Measles-Mumps-Rubella Vaccine; D017778:Vaccines, Combined; C050102:measles, mumps, rubella, varicella vaccine